Fuzzy logic based emergency flight control with thrust vectoring

ABSTRACT

A fuzzy logic based emergency flight control system for an aircraft. The system has a thrust vectoring flight control system, an aerodynamic flight control system, and a fuzzy logic controller. The thrust vectoring flight control system provides thrust to the aircraft in an emergency situation alone or in combination with aerodynamic flight controls. The fuzzy logic controller executes fuzzy logic algorithms for assessing the emergency situation and controlling the aircraft thrust vectoring and aerodynamic flight control systems in the emergency situation. An adjustable nozzle is coupled to an exhaust thrust end of an engine of the aircraft and is angularly adjusted to direct thrust of the aircraft in a determined direction after fuzzy logic controller assessment of the emergency situation. Alternatively, an adjustable panel is mounted to a wing of the aircraft and positionable near an exhaust thrust end of an engine of the aircraft to direct thrust of the aircraft in a determined direction after the fuzzy logic controller assessment of the emergency situation. The fuzzy logic controller further includes a position, attitude, and heading determination system for determining position, attitude, and heading of the aircraft. The position, attitude, and heading determination system further includes global positioning system receivers mounted at extremities of the aircraft and a determination processor coupled to the global positioning receivers for calculating and assessing position, attitude, and heading of the aircraft.

FIELD OF INVENTION

The invention relates to flight control of aircraft and, moreparticularly, to fuzzy logic based emergency flight control with thrustvectoring capability.

BACKGROUND

Sophisticated flight control systems are required to handle the complexrequirements of modern aircraft flight. As the number of aircraft andthe percent utilization of aircraft, specifically takeoffs and landings,increases, air traffic control (ATC) becomes more complicated.Heightened sensitivity and awareness of the importance of preventingmid-air collisions and other accidents increases with the increase inair traffic. Air traffic increases have resulted in more numerous flightpaths and less aircraft spacing. The demands put on aircraft navigationsystems have correspondingly increased.

Typically, transport aircraft use conventional aerodynamic flightcontrol (AFC) methods that involve maneuvering the aircraft by means ofthe aircraft control surfaces. These control surfaces, such as theailerons, elevators, and rudders, manipulate airflow to allow formodification of the aircraft flight path. Maneuverability of an AFCbased aircraft with a fixed thrust direction is controlled, to a lesserdegree, by changing engine thrust magnitudes. An increased researcheffort is being placed on modifying the direction of the engine thrustby nozzle redirection capabilities or external adjustable vanes.Controlling thrust direction is known as thrust vectoring. See U.S. Pat.Nos. 5,782,431; 5,769,317; 5,687,907; 5,628,272, each of which isincorporated herein by reference.

Thrust vectoring allows for much greater control of an aircraft and hasbeen studied extensively for use in military applications. Inhospitableconditions demand flexibility in the ability of the military to make useof various runway lengths for aircraft. When the only runway availableis very short, the need exists for an aircraft that is able to performvertical or short takeoffs and landings. The McDonnell Douglas/BritishAerospace AV-8B Harrier II is a military aircraft that is capable ofsuch maneuvers. Aircraft with variable type thrust delivery systems arecapable of vertical or short takeoffs and landings.

Commercial aircraft do not incorporate hardware for producing a verticalthrust component. In normal aircraft operating environments, withadequate runway lengths and the like, there has not been a need forthrust vectoring. The exception is the use of thrust deflectors that aredeployable upon landing to assist in slowing of the aircraft aftertouchdown. However, the inventor's believe that there is an unfulfilledneed to improve collision and meteorological hazard responsiveness inaircraft in general and in commercial aircraft in specific.

Aircraft are very safe modes of transportation but there is always thechance that an aircraft may be involved in a collision with anotheraircraft, lose altitude unexpectedly or impact an object fixed to theground.

“Controlled Flight into Terrain” is a term used to describe a situationwhere an aircraft, under control of the crew, is flown into terrain, anobstacle or water, with no prior awareness on the part of the crew ofthe impending collision. Avoidance of this type of mishap is addressedin this invention.

Another mishap this invention seeks to avoid is the loss of control ofthe aircraft due to weather and atmospheric phenomenon. Aircraftexperiencing turbulence, in particular wind shear, are at risk to suddenchanges in altitude. These sudden changes in altitude are, at theminimum, uncomfortable to passengers and crew and if radical willjeopardize the safety of the aircraft itself. This danger is morepronounced at takeoff and landing when the aircraft is at low altitude.The aircraft can lose altitude rapidly and possibly impact the grounddue to the effects of wind shear.

Wind shear is a natural phenomenon that occurs primarily duringthunderstorms. A large downburst of cold, dense air associated with afrontal system hits the surface of the earth and spreads horizontallyundercutting the warmer air outside the zone of the cold air downburst.The mixing of the cold and warm air produces a rolling vortex and causeshigh velocity winds to surge in opposite directions. This phenomena iswind shear. The hazard presented by wind shear, according to theNational Transportation Safety Board (NTSB), has, directly orindirectly, contributed to approximately fifty percent of all commercialairline fatalities between 1974 and 1985. The NTSB has determined thatover six hundred lives have been lost since 1964 due to the effects ofwind shear.

To help alleviate the problem caused by wind shear, all commercialcarriers were required to install some form of wind sheardetection/avoidance system on their aircraft by 1995. Various sensinghardware and techniques are available for an aircraft to determine if itis in a hazardous turbulence or wind shear condition. Methods andapparatuses designed for wind shear detection, such as Doppler radar,have been developed. Methods and apparatuses for position and attitudesensing, as well as wind shear detection, are necessary for theimplementation of an aircraft stabilizing system. Various configurationsof wind shear detection may be found in U.S. Pat. Nos. 5,050,087;5,406,489; 5,648,782; 5,523,759; 5,093,662, each of which isincorporated by reference herein.

Collision avoidance is one consideration of flight control systems.Collision avoidance schemes are largely dependent on efforts of airtraffic controllers tracking aircraft traffic. When a potential dangerbecame evident or was detected, the air traffic controller would notifyeach of the aircraft involved and provide alternative flight paths. Withthe increase in volume of air traffic, the air traffic controller'sresponsibilities have increased as well. What was once an acceptable andmanageable technique for managing the volume of aircraft has become lessmanageable. Aircraft intercommunications or ground based monitoringstations in conjunction with on board collision avoidance systems haveprovided for more effective collision avoidance infrastructure.

GPS based air traffic control and collision avoidance systems aredisclosed in U.S. Pat. Nos. 5,740,047; 5,714,948; 5,638,282; 5,636,123;5,610,815; 5,596,332; 5,450,329; 5,414,631; 5,325,302; 5,153,836; and4,835,537, each of which is incorporated herein by reference.

Emergency control using thrust vectoring has been proposed for transportaircraft (U.S. Pat. No. 5,782,431). This patent only describes theapparatus and its operation and does not disclose any system fordetection of the need for thrust vectoring. Specifically, it does notinclude any method of automatic control in the event of a dangeroussituation that may require an immediate action faster than a manualresponse implemented by the flight crew. The system disclosed hereinimplements a fuzzy logic based control scheme to analyze the dangerlevel and appropriately engage the thrust vectoring system, inconjunction with automatic flight control measures, for aircraftstabilization or collision avoidance.

Fuzzy logic is a well known and developed logic system which is asuperset of Boolean logic. Since the world is primarily analog innature, many situations cannot be analyzed in a simple binary analysis.Simply concluding that an event, element or condition is either “X” oris not “X” is seldom adequate in making a complex decision. For example,an aircraft's altitude cannot simply be distinguished by low or not low,high or not high. There are other factors that need to be factored intothe equation. For instance, an aircraft that is flying at twelvethousand feet altitude is not necessarily “low” but in a mountainousregion with peaks extending to twelve thousand feet “low” takes on arelevant new meaning. Fuzzy logic systems are designed to deal withthese nuances and assist in decision output results dependent on a setof operating rules.

Bivalent Set Theory is limiting as a decision making system, whenattempting to model problems involving “humanistic” issues, becausemembership in bivalent sets is mutually exclusive. To provide a level ofutility beyond that resulting from Bivalent Set Theory the theory ofFuzzy Logic or Fuzzy Set Theory was developed. Fuzzy Set Theory providesfor membership in more than one set thus allowing a transition band fromone set to another. As an example, instead of saying the air speed of anaircraft went from medium to fast in a change of 1 knot/hour (400knots=medium, 401 knots=fast), the fuzzy set theory permits the changeto happen over 10, 20, or 30 knots. This represents a transition bandwhere the speed has membership (of magnitude less than 1) in both themedium and fast sets.

If the current flight status (pilot commands, altitude, air speed,engine thrust magnitude, nozzle angle, etc.) and external weatherconditions (wind speed, wind shear magnitude, etc.) of an aircraft areknown, a fuzzy logic controller is able to make rapid decisions as tothe magnitude of a hazardous situation. The fuzzy logic controller canalso determine what corrective actions should be taken.

Providing fuzzy logic controllers with the ability to automaticallyengage both conventional aerodynamic flight control (CFC) and thrustvectoring flight control (TVFC), the fuzzy logic controller is able tomake decisions as to what combination of the two flight control systemswould best handle the hazardous situation.

Sophisticated systems for determining aircraft position exist andcontinue to be developed. Such systems are especially important to anemergency flight control system for controlling an aircraft in anemergency situation. One of the aeronautical navigation or geographicpositioning technologies that exists for determining aircraft positionis the global positioning system (GPS). In addition other navigation aidsystems are available. For instance, the global orbiting navigationsatellite system (GLONASS) is a system that is currently in use.

The core of GPS is a constellation of twenty-four (24) satellites whichcontinuously transmit information that are used by GPS based navigationequipment for position determination. Using differential GPS (DGPS),very accurate position information is attained for navigation and otherflight control functions. Various GPS based navigation techniques thatare used in conjunction with this invention include U.S. Pat. Nos.5,570,095; 5,548,293; 5,543,804, each of which is incorporated byreference herein. Since GPS systems provide very accurate and preciseinformation as to the aircraft's location, then GPS systems aredesirable systems that may be integrated into subsystems that can beused for flight control and/or emergency control of an aircraft.

There is an industry need for an improved flight control system forcontrolling an aircraft in emergency situations or for use in hands-offflight situations. The present invention discloses and provides a fuzzylogic based emergency flight control system with thrust vectoring andaerodynamic flight control capabilities, and the present inventionovercomes the problems, disadvantages, and limitations of the prior art.

SUMMARY OF THE INVENTION

This invention provides for a fuzzy logic based emergency flight controland warning system using GPS position information and incorporating bothaerodynamic flight control and thrust vectoring flight controltechniques. Although not directed exclusively to emergency flightcontrol systems, such emergency systems will be discussed in depthherein, however, this disclosure is intended to cover non-emergencyflight controls as well.

In this invention a fuzzy logic system is used to make importantdecisions concerning the flight trajectory of an aircraft. The decisionsinclude those concerned with, for example, the magnitude of danger thatexists and what type of corrective action should be taken to alleviatethe dangerous situation. Corrective action, triggered by the fuzzy logiccontroller, includes using aerodynamic flight control methods, thrustvectoring flight control methods, or a combination of the two systems.The invention also contemplates the use of data from an air trafficcontrol system that uses position information derived from the GPSreceivers. Such information will be input data to the fuzzy logicsystem. Based on the information input from the air traffic controlsystem the fuzzy logic controller determines if other aircraft in thearea pose a safety threat.

Air traffic control systems use bi-directional radio communications fortransmitting information between aircraft or ground monitoring stations.A terrain map containing information of ground objects (buildings,trees, mountains, and the like) provides information to the fuzzy logiccontroller. This information is used in the determination of themagnitude of danger that may exist relative to the aircraft with respectto ground objects.

The fuzzy logic controller of this invention uses GPS receivers locatedon the extremities of the aircraft to provide input for position,attitude, heading, and speed calculations. GPS has been developed for avariety of applications and uses. Differential GPS receivers have alsobeen developed and currently have the ability to resolve a receiverposition to an accuracy of one centimeter. Differential GPS relies uponground based correction stations having an exact known position toprovide differential GPS receivers information about the distortion ofthe satellite signals. The proposed invention provides emergency flightcontrol measures to prevent aircraft accidents, which requires preciseposition and attitude information for proper operation of the system.The flight information provided by the GPS receivers is also used in theair traffic control system when notifying other aircraft about a firstaircraft's position and heading.

This invention contemplates and discloses simultaneous use ofaerodynamic flight control surfaces and thrust vectoring controls usingadjustable engine nozzles or separate vanes/panels for flight and/oremergency control. The thrust vectoring aspect of flight controlprovides contemporary aircraft more flexibility in flight controloptions. This includes both aerodynamic flight control and the abilityto provide thrust components in more than one direction, includingthrust reversing which is useful in slowing the aircraft. Generally,thrust from the engines of the aircraft is redirected in a manner thatprovides a vertical component of thrust giving an aircraft a shortertakeoff and landing capability. Such thrust vectoring also providesenhanced protection from hazardous situations such as wind shear andturbulence. It is contemplated that thrust vectoring may also be used toavoid mid-air collisions between aircraft.

The fuzzy logic controller of this invention takes input from variousaircraft sensors, including GPS receivers, air traffic controlfacilities, and also the terrain map, to determine if the aircraft is ina dangerous situation. The fuzzy logic controller implements rule based“if-then” algorithms making constant calculations to determine themagnitude of danger that may exist and what actions to take to alleviatethe danger. For example, if aircraft experiences wind shear on takeoff,the danger level is extremely high due to the low altitude of theaircraft and minimal time available to correct the situation. In such asituation the fuzzy logic controller, after issuing a warningnotification to the flight crew, decides either to take immediate action(automatic flight control) by implementing the necessary thrustvectoring and/or aerodynamic flight control measures or to leaveaircraft control in the hands of the crew. The automatic flight controlaction taken to prevent unfortunate consequences resulting from windshear will be extreme because of the proximity to the ground and low airspeed. These extreme measures may be uncomfortable to the passengers butmay save lives by causing the aircraft to recover from the wind shearincident. In another type of situation, an aircraft experiencing severeturbulence at thirty thousand feet, the time available for the crew totake action to recover from a sudden loss of altitude is usuallyadequate. Thus the fuzzy logic controller may not necessarily dictateautomatic flight control and most likely will not dictate extremecorrective measures. The fuzzy logic controller in this case maydetermine either to allow the flight crew to handle the problem ordecide that it is able to improve the situation by the immediate andautomatic application of the necessary aerodynamic flight control andthrust vectoring flight control measures. The reason for some degree ofautomatic flight control would be to smooth the turbulence effects andimprove the quality of the passenger flight. In one variation of thehigh altitude circumstance, that being a situation wherein a secondaircraft is determined to be proximate the first aircraft due to asudden loss of altitude, the fuzzy logic controller may dictate thatpilot control be superseded by automatic flight control at the directionof the fuzzy logic controller.

The use of both aerodynamic flight control and thrust vectoring flightcontrol measures increases the overall ability of the aircraft to averthazardous or dangerous situations and improve the flight quality for thebenefit of the passengers.

The invention also incorporates an air traffic control system, whichbroadcasts the position of a first aircraft and receives positioninformation of all aircraft in a specific region. A two-way radio systemprovides the communications between aircraft and a ground monitoringstation. Information from the air traffic control system is displayed tothe flight crew and is also monitored by the fuzzy logic controller todetermine if a potential threat to the first aircraft exists.

A terrain mapping system is also used as an input to the data processingin the fuzzy logic system. The terrain map provides information to thefuzzy logic controller about all ground-based objects in the area orflight path of the aircraft. The terrain map also includes informationabout the position of all geographic objects such as hills, mountains,trees, buildings, towers, power lines, signs, and like hazards. The mapof all ground-based objects provides critical accident preventioninformation when conditions require flying an aircraft by instrumentsalone (IFR). If the fuzzy logic controller detects the aircraftapproaching an object identified in the terrain map, it immediatelyprovides the flight crew with a warning of the level of danger orautomatically takes immediate emergency flight control measures toprevent an impending collision.

Warning indicators on board the aircraft provide the flight crew withthe current status of flight situations or conditions. The warningindicators may be one of many alarm options to provide the flight crewwith information about possible hazardous or dangerous situations.Warnings are both visual and audible. Audible warnings may be in theform of simple tones, intense alarms, or synthetic speech, to provideimportant flight crew hazard warning if the flight crew's attention hasbeen diverted from the visual warning system.

It is an object of this invention to provide a fuzzy logic based controlsystem that makes determinations of the magnitude of a hazardous ordangerous situation, that an aircraft may be experiencing. The controlsystem includes a fuzzy logic controller that receives a plurality ofinputs from the various aircraft sensors, including GPS receivers, anair traffic control facility, and terrain map of ground based objects.

It is another object of this invention to implement the fuzzy logiccontroller using if-then inference rule base fuzzy logic algorithms. Thefuzzy logic controller determines the level of danger that exists andwhat corrective measures needs to be taken to avert a disaster ordangerous situation.

It is another object of this invention to make use of both aerodynamicflight control and thrust vectoring flight control for stabilizing anaircraft in dangerous or emergency situations. The fuzzy logiccontroller makes the determination of when and to what extent the twoflight control systems are used in different dangerous or emergencysituations.

It is an object of this invention to use GPS receivers located atoptimal locations about the extremities of the aircraft to providecritical position, heading, and speed information for input to the fuzzylogic controller and air traffic controller functions.

It is an object of this invention to implement an air traffic controlsystem that provides inputs to the fuzzy logic controller, which isprocessed to make determinations of dangerous or hazardous flightsituations such as possibilities of mid-air collisions with otheraircraft in the area. The system transmits and receives GPS navigationinformation directly from other aircraft or ground monitoring stations.The air traffic control system displays traffic information about allaircraft in a given area.

It is an object of this invention to implement automatic flight controlmeasures when necessary. When a hazardous or dangerous condition isdetected by the fuzzy logic controller and the aircraft is not beingproperly controlled to avoid the condition or the flight danger isimminent, the fuzzy logic controller performs the necessary emergencyflight control measures, aerodynamic flight control, and/or thrustvectoring flight control to prevent an accident or dangerous situation.

It is another object of this invention to use a terrain map to provideinput about ground based objects to the fuzzy logic controller. Theterrain map is a geographic information system providing criticalinformation about the position and size of ground-based objectsincluding mountains, buildings, towers, trees, and the like. When thefuzzy logic controller detects a possible danger with an object on theground, it may take the necessary danger/emergency aerodynamic flightcontrol and/or thrust vectoring flight control measures or it may simplyalert the flight crew if the danger is not imminent.

The above objects and advantages of the invention are achieved by afuzzy logic based emergency flight control system for an aircraft. Thesystem has a thrust vectoring flight control system and a fuzzy logiccontroller. The thrust vectoring flight control system provides thrustto the aircraft in an emergency situation. The fuzzy logic controllerexecutes fuzzy logic algorithms for assessing the emergency situationand controlling the aircraft in the emergency situation. An adjustablenozzle is coupled to the engines of the aircraft. The nozzle is adjustedto direct thrust of the aircraft in a determined direction after thefuzzy logic controller has assessed the emergency situation.Alternatively, an adjustable panel is mounted to a wing of the aircraftand can be positioned near the engine exhaust. The panel is can beadjusted to direct thrust of the aircraft in a determined directionafter the fuzzy logic controller has assessed the emergency situation.

An aerodynamic flight control system is coupled to the fuzzy logiccontroller for providing control to the fuzzy logic controller ofaerodynamic controls of the aircraft in the emergency situation. Theaerodynamic flight control system further includes a control surfacesystem for controlling control surfaces, such as flaps, ailerons, andstabilizers of the aircraft. The fuzzy logic controller further includesa central processing unit which executes algorithms and applications forcontrolling the aircraft in the emergency situation.

The fuzzy logic controller further includes a position and attitudedetermination system for determining position and attitude of theaircraft. The position, attitude, and heading determination systemfurther includes global positioning system receivers mounted atextremities of the aircraft and a determination processor coupled to theglobal positioning receivers for calculating and assessing position,attitude, and heading of the aircraft. The fuzzy logic controllerfurther includes an aircraft position monitoring system, acommunications system, a display device, and a terrain map.

The above objects and advantages of the invention are also achieved by amethod of using a fuzzy logic based emergency flight control system foran aircraft. A thrust vectoring flight control system is operated forproviding thrust to the aircraft in an emergency situation. A fuzzylogic controller that is coupled to the thrust vectoring flight controlsystem is used to execute fuzzy logic algorithms for assessing theemergency situation and controlling the aircraft using the thrustvectoring flight control system in the emergency situation. Anaerodynamic flight control system is also coupled to the fuzzy logiccontroller used for providing control to the aerodynamic controls of theaircraft in the emergency situation. Control surfaces of the aircraftare controlled by the fuzzy logic controller.

The above objects and advantages of the invention are achieved by afuzzy logic method for controlling an aircraft in an emergencysituation. Input variables such as altitude, wind shear, air speed, andproximity parameters related to the aircraft are obtained, andcommunicated to a fuzzy logic controller. Further input variables may becurrent thrust magnitude and current thrust angle. The input variablesare fuzzified into input fuzzy sets using the fuzzy logic controller.The output variables are converted into output fuzzy sets. The outputfuzzy sets are used to calculate crisp output values for controlling theaircraft in the emergency situation. Commands based on the crisp outputvalues are executed, and the commands control the aircraft in theemergency situation.

Inference rule tables, a process component of fuzzy logic, are used toconvert the output variables into the fuzzy sets. Total lift requiredfor recovery from the emergency situation is determined and calculatedfrom a sum of thrust from thrust vectoring flight control commands andthrust from aerodynamic flight control commands. A ratio of thrustbetween the thrust vectoring flight control commands and the aerodynamicflight control commands is determined. The inverse ratio between theaerodynamic flight control commands and the thrust vectoring flightcontrol commands alternatively can be determined. Inference rules areused to determine the total thrust.

The above objects and advantages of the invention are also achieved byan aircraft position, attitude, and heading determination system. Thesystem includes global positioning system receivers mounted at variouslocations of the aircraft and a determination processor coupled to theglobal positioning receivers for calculating and assessing position,attitude, and heading of the aircraft. The global positioning systemreceivers are located at extremities, such as nose of the aircraft, tailof the aircraft, left and right wing tips of the aircraft. The globalpositioning system receivers and the determination processor alsodetermine angle of attack of the aircraft.

The preferred embodiments of the inventions are described below in theFigures and Detailed Description. Unless specifically noted, it isintended that the words and phrases in the specification and claims begiven the ordinary and accustomed meaning to those of ordinary skill inthe applicable art or arts. If any other meaning is intended, thespecification will specifically state that a special meaning is beingapplied to a word or phrase. Likewise, the use of the words “function”or “means” in the Detailed Description is not intended to indicate adesire to invoke the special provisions of 35 U.S.C. Section 112,paragraph 6 to define the invention. To the contrary, if the provisionsof 35 U.S.C. Section 112, paragraph 6, are sought to be invoked todefine the inventions, the claims will specifically state the phrases“means for” or “step for” and a function, without also reciting in suchphrases any structure, material, or act in support of the function. Evenwhen the claims recite a “means for” or “step for” performing afunction, if they also recite any structure, material or acts in supportof that means of step, then the intention is not to invoke theprovisions of 35 U.S.C. Section 112, paragraph 6. Moreover, even if theprovisions of 35 U.S.C. Section 112, paragraph 6, are invoked to definethe inventions, it is intended that the inventions not be limited onlyto the specific structure, material or acts that are described in thepreferred embodiments, but, in addition, include any and all structures,materials or acts that perform the claimed function, along with any andall known or later-developed equivalent structures, materials or actsfor performing the claimed function.

For example, the disclosed system uses GPS for navigation and otherfunctions. The navigation could also be implemented using GLONASS,combination of GPS and GLONASS, or any other navigation system providingthe necessary performance.

Likewise, the disclosed system makes use of a thrust vectoring system,in conjunction with aerodynamic flight control measures, to stabilizethe aircraft under adverse conditions such as wind shear. This systemcould be implemented using any suitable thrust vectoring techniquesheretofore known or hereinafter developed.

Likewise, there are disclosed several computers, controllers, andsystems that perform various control operations. The specific form ofthe computer, controller, or system is not important to the invention.Any computer, controller or system now known or hereafter known ordeveloped that is capable of performing the functions, processes ormethods disclosed herein may be used in the implementation of thisinvention. In its preferred form, the necessary computing steps orcontrol steps are able to be implemented into existing flight controlcomputers.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention disclosed in this application will be readily understoodwhen considered in conjunction with the following drawings and detaileddescription of the preferred embodiments. The various hardware andsoftware elements as well as the methods and processes used to carry outthe invention are illustrated in the attached drawings in the form ofblock diagrams, flow charts, and other illustrations. The invention isnot limited to the depictions in the drawing figures.

FIG. 1a shows graph diagrams of the fuzzification process for thepresent fuzzy logic based emergency flight control system with thrustvectoring to convert input variables into fuzzy sets with triangularoverlapping membership functions.

FIG. 1b shows graph diagrams of the fuzzification process for thepresent fuzzy logic based emergency flight control system with thrustvectoring to convert output variables into fuzzy sets with triangularoverlapping membership functions.

FIG. 2a shows an example of inference rule tables used in the fuzzylogic process for wind shear flight control using the present invention.

FIG. 2b shows an example of inference rule tables (continuation fromFIG. 2a) used in the fuzzy logic process for wind shear flight controlusing the present invention.

FIG. 3a shows an example of inference rule tables for determining thetotal lift required for a hazardous situation involving a possiblecollision.

FIG. 3b shows triangular membership functions for input variablesdefining distance to an object and relative airspeed, and outputvariable of the total lift required.

FIG. 4a shows an example of an inference rule table for determining theratio between thrust vectoring lift and the total lift required.

FIG. 4b shows triangular membership functions for input variablesvertical acceleration and altitude, and output variable of the ratio ofthrust vectoring flight control (TVFC)/aerodynamic flight control (AFC).

FIG. 5 shows a perspective view of an aircraft having GPS receiverslocated on the extremities of the aircraft.

FIG. 6 shows a bottom view of a standard aircraft.

FIG. 7a shows a side view of an adjustable thrust vectoring nozzle in ahorizontal thrust position.

FIG. 7b shows a side view of an adjustable thrust vectoring nozzle in avertical and horizontal thrust position.

FIG. 8 shows a side view of an adjustable thrust vectoring nozzleincorporating a separate adjustable vane or panel.

FIG. 9 shows a block diagram of the fuzzy logic controller and itsvarious control and operational systems.

DETAILED DESCRIPTION OF THE DRAWINGS

The present invention can be broadly described as an emergency flightcontrol system that uses a fuzzy logic based system to determine actionsin furtherance of avoiding the consequences of an emergency. Theinvention also provides for thrust vectoring capability for use withaircraft using such an emergency flight control system. The proposedfuzzy logic controller (FLC) 59 (which is shown in FIG. 9) is similar toconventional control systems in that it operates on inputs, performssome calculations, and generates an output value. The process that isused is called the Fuzzy Inference Process and is defined by thefollowing three general steps: 1) the fuzzification step which involvescrisp data inputs that are translated into fuzzy values; 2) the ruleevaluation or inference step which involves the calculation of fuzzyoutput truth values; 3) the defuzzification step which involves a crispvalue that is derived from the fuzzy outputs.

FIG. 1a demonstrates the fuzzification process for the input variablesaltitude, wind shear magnitude, air speed, thrust magnitude, nozzleangle, and proximity to other aircraft or ground objects and outputvariables of thrust magnitude and nozzle angle. This is only arepresentative list of possible variables. Many other aircraftparameters that currently exist such as air density, or that come intobeing in the future such as wind shear angle or direction, may be usedin the fuzzy logic process. The individual graph variables are fuzzifiedinto fuzzy sets. The fuzzy set for altitude in FIG. 1a demonstratestriangular (one possible shape) membership functions (fuzzy subsets) forthe possible altitude input categories: very low, low, medium, high,very high. The triangular membership functions are overlapping whichprovides for crisp input values to have membership in more than one ofthe altitude categories. For example, a specific altitude (crisp inputvalue) may belong to both the medium and high membership functions (orany two adjacent categories). Membership in an input variable categoryis never greater than one and whenever one category is at a maximum(membership=1), adjacent categories will be at a minimum (membership=0).The set that contains all possible values for a given input variable isreferred to as the universe of discourse.

Output variables must also be converted to fuzzy sets. FIG. 1billustrates two possible output variables, which have been fuzzified.Thrust vectoring nozzle angle (TVFC) and thrust magnitude (AFC) havebeen converted to fuzzy sets, which are used in the defuzzificationprocess to calculate crisp output values after the rule evaluationprocess has been completed. Other possible TVFC and AFC output variablesinclude: flap angle, aileron angle, engine thrust magnitude, and thelike. The output fuzzy sets seen in FIG. 1b demonstrate the ability ofthe fuzzy logic controller (FLC) to generate both TVFC and AFC outputcontrol actions.

Rule (or knowledge) based if-then statements (inference rules) aredefined based upon an in depth knowledge of the aerodynamics of aparticular aircraft and the possible dangers the aircraft may encounter.FIGS. 2a-2 f illustrate inference rule tables, that are used to evaluatethe input variables for air speed, altitude, and wind shear magnitude toproduce a TV nozzle angle for the appropriate emergency response in agiven hazardous condition. FIG. 2a is the inference rule table for theair speed category of very low demonstrating the rules to be evaluatedin a situation such as might be encountered during takeoff or landing inthe presence of a wind shear. Categories for altitude of the aircraftare on placed across the top row and the categories for wind shear areplaced down the leftmost column. The output variable to be determined isthe angle of the thrust vectoring nozzle; the higher the angle the morevertical thrust produced to counteract the downward force of the windshear. With greater aircraft altitude, less extreme the TV nozzle anglesare needed because standard AFC recovery measures at the higher altitudecan possibly provide a more effective solution. Examples of rulesdefined in the rule table of FIG. 2a for very low wind speed are:

a) IF air speed=very low AND altitude=very low AND wind shear mag.=veryweak THEN nozzle angle=very steep.

b) IF air speed=very low AND altitude=low AND wind shear mag.=weak THENnozzle angle=steep.

c) IF air speed=very low AND altitude=very high AND wind shearmag.=medium THEN nozzle angle=medium.

If the air speed is very high, the rules for the same categories ofaltitude and wind shear magnitude are:

a) IF air speed=very high AND altitude=very low AND wind shear mag.=veryweak THEN nozzle angle=steep.

b) IF air speed=very high AND altitude=low AND wind shear mag.=weak THENnozzle angle=medium.

c) IF air speed=very high AND altitude=very high AND wind shearmag.=medium THEN nozzle angle=low.

The inference rules clearly demonstrate that as the air speed increases,the need for extreme TVFC based emergency measures diminishes. Properlydefined inference rules for TVFC and AFC emergency measures allows thetwo flight control systems to complement each other in avoiding manydangerous situations which would not be possible using just theindividual flight control systems.

The inference rules disclosed are exemplary for an aircraft in thesituation described above. Detailed inference rules are provided by anexpert who has an in depth knowledge of the flight dynamics of aspecific aircraft. The expert, or experts, have an intimate knowledge ofhow the specific aircraft would react to the applied combination ofconventional and thrust vectoring control commands issued for thedifferent hazardous situations.

After the rule evaluation process (inference), the degree of truth ofthe output variables has been determined. The output fuzzy sets areoverlapping membership functions which must be defuzzified fordetermination of a crisp value which is meaningful to the flight controlprocess. For example, if it was determined in the inference process thatthe nozzle angle had a degree of truth of being steep of 0.6 and adegree of truth of 0.4 that the angle is medium, the automatic flightcontrol systems will not have enough information to be able to set thenozzle angle to a discrete value. Several methods have been developed toproduce crisp values from the combined output values calculated duringthe inference process. The centroid (center of mass) method is anexample of a popular defuzzification technique.

The above described fuzzy logic thrust vectoring control is combinedwith conventional aerodynamic flight control (AFC) by considering thetotal resultant vertical lift to be a combination of the thrust fromthrust vectoring control and aerodynamic flight control systems. Inother words, the total lift is the sum of thrust provided by twocomponents: the first being from thrust vectoring (TV) and the secondfrom aerodynamic flight control (AFC). Determining the ratio of thrustvectoring flight control to aerodynamic flight control required for agiven hazardous situation allows for more flexible emergency flightcontrol methods to help prevent mid-air collisions and crashes withground based objects. The total lift required to avert a hazardoussituation is calculated using the fuzzy logic process (fuzzification,rule evaluation, defuzzification) and input variables as previouslydescribed. Inference rules are defined for the output variable of totallift required in the same manner as for the previously described outputof thrust vectoring nozzle angle.

FIG. 3a demonstrates example inference rules for calculation of thetotal lift required to avoid a current hazardous situation. Theinference rules use distance from the object (i.e. to other aircraft orground based object) and relative velocity/acceleration of the aircraft,with respect to the collision hazard, as inputs for the inference ruleevaluation. FIG. 3b shows membership functions for distance from theobject having categories of very close (VC), close (C), medium (M), far(F), and very far (VF). Airspeed of the aircraft has membershipfunctions with categories of very low (VL), low (L), medium (M), high(H), and very high (VH). After calculation of a crisp value for therequired lift, another fuzzy logic calculation is performed to determinethe thrust vectoring flight control to total lift ratio(lift_(TVFC)/lift_(TOTAL)), which is the portion of lift from thrustvectoring control required to handle the current hazardous situation.

As an example of the (lift_(TVFC)/lift_(TOTAL)) calculation for anaircraft experiencing a wind shear, the altitude and verticalacceleration of the aircraft are used in the fuzzy logic calculation.Vertical acceleration is a measured quantity representing the magnitudeof the wind shear experienced by the aircraft. If the wind shearmagnitude is large the aircraft will experience a large accelerationdownward. FIG. 4a shows possible inference rules relating inputcategories of altitude and vertical acceleration with the outputcategory of lift_(TVFC)/lift_(TOTAL). Membership functions for altitude,and vertical acceleration, and lift_(TVFC)/lift_(TOTAL) can be seen inFIG. 4b. The inference rules demonstrate the need for a greater thrustvectoring component (larger lift_(TVFC)/lift_(TOTAL)) as altitudedecreases or vertical acceleration increases.

With the known lift_(TVFC)/lift_(TOTAL) ratio, the portion of lift to beperformed by the aerodynamic flight control (AFC) systems (i.e.lift_(AFC)/lift_(TOTAL)) will be the remainder of the total thrustrequired, that is:

lift_(AFC)/lift_(TOTAL)=1−lift_(TVFC)/lift_(TOTAL).

Alternatively, the lift_(AFC)/lift_(TOTAL) ratio could have beendetermined from the fuzzy logic process, and the portion of liftrequired from the thrust vectoring systems would have been theremainder, that is:

lift_(TVFC)/lift_(TOTAL)=1−lift_(AFC)/lift_(TOTAL).

In determining these ratios, a fuzzy logic combined thrust vectoring andaerodynamic flight control is achieved. Thrust vectoring is used asappropriate to augment conventional control for emergency flight controlcorrections.

The proposed invention uses the global positioning system (GPS) forposition, heading, and speed input to the fuzzy logic controller (FLC).FIG. 5 shows the location of four GPS receivers on a typical aircraft 8.There are receivers mounted at the front 10 a and rear 10 b, and alsothe left and right wing tips 10 c, 10 d. These receivers have sufficientchannels to allow continuous monitoring of all satellites in view (up to12 for GPS). Multiplexing of channels may cause delays in locking timeand update rate, which would be unacceptable for many emergencyconditions. Input from these four GPS receiver locations can provide theFLC with data to calculate position, attitude (roll, pitch, and yaw),and heading. Angle of attack (angle between attitude and direction offlight) can also be calculated. Position, attitude, and headinginformation is updated at a sufficient rate to determine if the aircraftis in a hazardous condition such as possible collision, stall, spin,wind shear, etc.

The bottom view of a typical four engine jet aircraft 8 is illustratedin FIG. 6. In conventional or aerodynamic flight control (AFC), theengines 12 provide thrust for the aircraft in a horizontal directionallowing air to flow over and under the wing (and other controlsurfaces) providing lift for the aircraft. Air input 14 to the engine at16 is compressed and burned with the jet fuel. The expanding gases arepropelled out the nozzles 18 producing thrust 20, which in turn producesa force on the aircraft 22 in the opposite direction. The majority ofaircraft today have fixed nozzles, which produce thrust in primarily ahorizontal direction. The nozzles of this invention are adjustableproviding a thrust vectoring capability.

This invention uses both AFC and thrust vectoring flight control (TVFC)for emergency flight control measures. TVFC uses an adjustable nozzle orvane to redirect the engine thrust. FIG. 7a shows the adjustable enginenozzle in the position used for horizontal flight. The nozzle lies closeto the horizontal axis of the engine 24. This position of the nozzleused in conjunction with standard control surfaces (flaps, ailerons,stabilizer, etc.) represents a configuration similar to most jetaircraft. In the horizontal flight mode, the nozzle 28 is directed in ahorizontal direction providing only one component of thrust 30 also in ahorizontal direction. FIG. 7b demonstrates the concept of a thrustvectoring adjustable engine nozzle. When the aircraft requiresadditional lift or emergency maneuvering (stall, wind shear, collision,etc.) the nozzle 32 can be redirected at a downward angle θ 34 withrespect to the horizontal axis of the engine 24. The total thrust 36 atthe angle θ provides a component of thrust in both the vertical 38 andhorizontal 40 directions. The vertical component of thrust 38 providesgreater lift to the aircraft than could be achieved by airflow over thecontrol surfaces alone.

In another embodiment of the invention, thrust vectoring is accomplishedwith a vane/panel that is moved into the flow of exhaust to redirect thethrust. FIG. 8 demonstrates how the thrust 42 flows from the fixednozzle 44 in a horizontal direction. When the fuzzy logic controller(FLC) 59 determines the aircraft is in a hazardous situation, the thrustvectoring vane 46 is moved into place using actuators 48, which areattached to the wing 50. The thrust is redirected at an angle θ 54 tothe horizontal axis of the engine 24. This redirection of the thrust 54now contributes a component of thrust in the vertical direction 52. Theactuators can control the position at which the thrust vectoring vane ispositioned controlling the angle θ 54 which directly relates to themagnitude of the thrust component in the vertical direction. FIGS. 7 and8 demonstrate two dimensional control methods but the thrust vectoringsystems may also be designed to provide a three dimensional capability.

The FLC is the central component of the proposed system. The FLC may bea single system or a central computer with multiple embedded systems forindividual functions (GPS, communications, terrain map, etc.). A blockdiagram of the FLC 59 is shown in FIG. 9. The CPU 60 is the core of theFLC, which executes the application and system level software for theemergency flight control and associated functions. Calculation of fuzzylogic algorithms 76 are performed by the CPU. The CPU has amicroprocessor, memory (RAM and ROM), application/data storage devices,such as, but not limited to disk drives, input/output ports (forcommunication with the outside world), and other relevant hardware forimplementation of the processing functions. This system could also be anoff the shelf computer with at least all the hardware functionsdescribed above.

It is important to know the exact position, attitude, and speed of theaircraft at all times. It is not only important for the emergency flightcontrol system proposed by this invention, but this information is alsonecessary in the normal flight operations of the aircraft. In FIG. 9 theGPS receiver input 62 used in this invention provides coordinateinformation to the position/attitude function 64 of the FLC. Theaerodynamic flight control function 66 manipulates the control surfaces(flaps, ailerons, stabilizers, etc.) 68. The thrust vectoring flightcontrol function 70 manipulates the adjustable nozzle (or vanes) of thethrust vectoring system when the FLC determines that an emergencysituation exists. Thrust vectoring allows the capability of suddenchanges in the flight path of the aircraft, which cannot be performed bythe AFC system alone. In the event of an unexpected wind shear ontakeoff or landing, AFC measures alone may not provide sufficientvertical lift to overcome the downward force of the wind shear. Withautomatic engagement of the TV nozzles in a downward manner, enoughvertical thrust may be generated to prevent the aircraft from crashinginto the ground. Another hazardous situation in which an aircraft mayrequire a sudden change in flight path is a possible mid-air collision.In this scenario the aircraft may require an immediate correction in itsflight path which could be in any direction. The fuzzy logic controllercalculates the level of danger to be high and also determines the bestcorrective action to take. Due to the FLC's capability to react fasterthan the flight crew, many potentially fatal mid-air collisions could beaverted.

Another feature of the FLC of this invention is the aircraft positionmonitoring function 86. This is an on board air traffic control (ATC)system used for collision avoidance. All aircraft in a given region willbroadcast their position, using the communications subsystem 84, to allother aircraft 92 and/or to a ground control station 90. A groundcontrol station accepts position information from all aircraft andbroadcasts this information to other aircraft in the area. The groundstation determines if a collision is possible and/or transmits positioninformation permitting the individual aircraft to determine if ahazardous condition exists. Ground stations are not necessary ifcommunications exists between all aircraft in the region. The positioninformation received about the other aircraft in the region is displayedon a graphics device 88. The display device may be a two dimensionaldevice displaying relative aircraft positions and identificationinformation. As an alternative, the display device may be threedimensional, which gives the flight crew an immediate sense of depthperception. The aircraft position monitoring 86 function provides datato the fuzzy logic processing 76 to make determinations of any collisiondanger, which may exist. If a danger exists the flight crew isimmediately notified and possible automatic emergency measures may betaken.

Another feature of this invention is the terrain map 78, which is a database containing all obstacles which may present a danger to theaircraft. The terrain map is a geographic information system (GIS)containing the coordinates of hazards such as trees, mountains,buildings, towers, etc. in a given area. The terrain map worksintegrally with position information from the position/attitude function64 and the FLC. Current position and heading information from the GPSreceivers is compared to information stored in the terrain map 78. If apotentially hazardous situation is detected by the fuzzy logiccontroller, the flight crew is notified or the FLC can take immediateemergency measures to avert a possible disaster.

The FLC must interact with the normal flight operations 80 to coordinatethe emergency actions and implement visual and audible warnings 82.Pilot inputs 81 to aircraft controls may be input variables to the fuzzylogic inference process 76. Such inputs may be helpful in determining ifthe aircraft may be in possible danger. For example, if the aircraft isapproaching a mountain range and the pilot commands the aircraft todescend, the FLC would make a determination as to the level of dangerthat this command represents. If the altitude of the aircraft is notsufficient to clear the mountain while descending, the FLC will providea warning to the flight crew or take immediate action. Emergency controlmeasures without pilot input are performed by the automatic flightcontrol function 94 in the FLC. Once the determination has been made (inthe fuzzy logic process) that the current situation requires immediateaction, the automatic flight control function sends the proper controlinformation to the flight control AFC and TVFC functions 66,70 and theproper warning indicators 82.

In summary one embodiment has been presented for implementing a fuzzylogic based emergency flight control system for aircraft. The systemincorporates a thrust vectoring ability for providing thrust tocomplement the conventional flight control systems. A fuzzy logiccontroller provides for an ability to determine the magnitude of ahazardous situation and what actions should be take to correct thesituation. The fuzzy logic controller provides for warning of the flightcrew of hazardous situations and takes automatic corrective actions ifnecessary.

The inventions set forth above are subject to many modifications andchanges without departing from the spirit, scope or essentialcharacteristics thereof. Thus, the embodiments explained above should beconsidered in all respect as being illustrative rather than restrictiveof the scope of the inventions as defined in the appended claims. Forexample, the present invention is not limited to the specificembodiments, apparatuses and methods disclosed for aircraft flightcontrol. The present invention is also not limited to the use of GPScommunication satellites and GPS receivers to determine locationsthroughout the system. The present invention is also not limited to anyparticular form of computer or computer algorithm.

We claim:
 1. A fuzzy logic based flight control system for a jet engineequipped aircraft, said aircraft having a jet engine exhaust thrustport, said flight control system comprising: a thrust vectoring flightcontrol system carried by said aircraft, and a fuzzy logic controller,including a set of fuzzy logic algorithms, said fuzzy logic controllerconnected to said thrust vectoring flight control.
 2. The fuzzy logicbased flight control system according to claim 1 wherein said thrustvectoring flight control system further comprises: an adjustable nozzlecoupled to said exhaust thrust port of said engine of the aircraft, saidadjustable nozzle is angularly adjustable to direct thrust of theaircraft in a determined direction responsive to said fuzzy logiccontroller.
 3. The fuzzy logic based flight control system according toclaim 2 further comprising an aerodynamic flight control system coupledto said fuzzy logic controller.
 4. The fuzzy logic based flight controlsystem according to claim 3 wherein said aerodynamic flight controlsystem further comprises a control surface system for controllingcontrol surfaces of the aircraft.
 5. The fuzzy logic based flightcontrol system according to claim 4 wherein said control surface systemfurther comprises: a flap control system for controlling flaps of theaircraft, an aileron control system for controlling ailerons of theaircraft, a stabilizer control system for controlling stabilizers of theaircraft.
 6. The fuzzy logic based flight control system according toclaim 3 wherein said fuzzy logic controller further comprises a centralprocessing unit, said central processing unit capable of executing saidfuzzy logic algorithms for controlling said aircraft.
 7. The fuzzy logicbased flight control system according to claim 6 wherein said centralprocessing unit further comprises: a microprocessor for executingprocessing commands, a memory device coupled to the microprocessor, astorage device coupled to the microprocessor, input and output portscoupled to the microprocessor for providing external communication andinterface, and a hardware system coupled to the microprocessor forimplementing processing commands.
 8. The fuzzy logic based flightcontrol system according to claim 1 wherein said thrust vectoring flightcontrol system further comprises an adjustable panel mountable to saidaircraft near an exhaust thrust port wherein the adjustable panel isangularly adjusted to direct thrust of the aircraft in a determineddirection responsive to said fuzzy logic controller.
 9. The fuzzy logicbased flight control system according to claim 1 wherein the fuzzy logiccontroller further comprises a position, attitude, and headingdetermination system.
 10. The fuzzy logic based flight control systemaccording to claim 9 wherein said position, attitude, and headingdetermination system further comprises: a global positioning systemreceiver mounted to said aircraft, and a determination processor coupledto said global positioning receiver, said determination processorcapable of calculating and assessing position, attitude, and heading ofsaid aircraft.
 11. The fuzzy logic based flight control system accordingto claim 10 wherein more than one of said global positioning receiversare mounted to said aircraft with one of said global position receiversmounted to a front portion, a rear portion, a left wing portion, and aright wing portion of said aircraft.
 12. The fuzzy logic based flightcontrol system according to claim 1 wherein said fuzzy logic controllerfurther comprises an aircraft position monitoring system capable ofdetermining and monitoring the area proximate said aircraft and an areaoutside the area proximate said aircraft.
 13. The fuzzy logic basedemergency flight control system according to claim 1 wherein said fuzzylogic controller further comprises a communications system.
 14. Thefuzzy logic based flight control system according to claim 13 whereinsaid communications system is capable of broadcasting a signal.
 15. Thefuzzy logic based flight control system according to claim 13 whereinthe communications system communicates to a ground station.
 16. Thefuzzy logic based flight control system according to claim 1 whereinsaid fuzzy logic controller further comprises a display device.
 17. Thefuzzy logic based flight control system according to claim 16 whereinsaid display device is a two dimensional display device for displayingrelative aircraft positions and aircraft identification information. 18.The fuzzy logic based flight control system according to claim 16wherein said display device is a three dimensional display device forproviding immediate sense of depth perception.
 19. The fuzzy logic basedflight control system according to claim 1 wherein said fuzzy logiccontroller further comprises a terrain map for providing geographicinformation related to terrain of an area to the aircraft.
 20. A fuzzylogic based flight control system for a jet engine equipped aircraft,said aircraft having a jet engine exhaust thrust port, said flightcontrol system comprising: a thrust vectoring flight control systemcarried by said aircraft; a fuzzy logic controller, including a set offuzzy logic algorithms, said fuzzy logic controller communicating withsaid thrust vectoring flight control system; an adjustable nozzlecoupled to said exhaust thrust port of said engine, said adjustablenozzle angularly adjustable to direct thrust of said engine in adirection responsive to said fuzzy logic controller; an aerodynamicflight control system coupled to said fuzzy logic controller, saidaerodynamic flight control system including a control surface system.21. The invention in accordance with claim 20 wherein said controlsystem comprises: a flap control system, an aileron control system, astabilizer control system.
 22. The invention in accordance with claim 21wherein said fuzzy logic controller further comprises a centralprocessing unit comprising: a microprocessor, a memory device coupled tosaid microprocessor, a storage device coupled to said microprocessor,input and output ports coupled to said microprocessor, and a hardwaresystem coupled to said microprocessor.
 23. The invention in accordancewith claim 22 wherein said fuzzy logic controller further comprises: aposition, attitude, and heading determination system comprising: aglobal positioning system receiver mounted to said aircraft, and adetermination processor coupled to said global positioning systemreceiver, said determination processor capable of calculating andassessing position, attitude, and heading of said aircraft.
 24. Theinvention in accordance with claim 23 wherein more than one of saidglobal positioning receivers are mounted to said aircraft with one ofsaid global position receivers mounted to a front portion, one to a rearportion, one to a left wing portion, and one to a right wing portion ofsaid aircraft.
 25. The invention in accordance with claim 23 whereinsaid determination processor system is capable of determining andmonitoring the area proximate said aircraft and an area outside the areaproximate said aircraft.
 26. The fuzzy logic based flight control systemaccording to claim 1 wherein said fuzzy logic controller furthercomprises an aircraft position monitoring system capable of determiningand monitoring the area proximate said aircraft and an area outside thearea proximate said aircraft surrounding area of the aircraft.
 27. Thefuzzy logic based flight control system according to claim 20 whereinsaid fuzzy logic controller further comprises a communications systemcapable of broadcasting a signal to a ground station.
 28. The fuzzylogic based flight control system according to claim 20 furthercomprising a three dimensional display device for providing relative aircraft positions, aircraft identification information and immediate senseof depth perception.
 29. The fuzzy logic based flight control systemaccording to claim 20 wherein said fuzzy logic controller furthercomprises a terrain map containing geographic information related toterrain of an area proximate to said aircraft.
 30. A fuzzy logic basedflight control system for a jet engine equipped aircraft, said aircrafthaving a jet engine exhaust thrust port, said flight control systemcomprising: a thrust vectoring flight control system carried by saidaircraft; a fuzzy logic controller, comprising: a microprocessor, amemory device coupled to said microprocessor, a storage device coupledto said microprocessor, input and output ports coupled to saidmicroprocessor, and a hardware system coupled to said microprocessor; aset of fuzzy logic algorithms, and; data input to said fuzzy logiccontroller comprising: a position, attitude, and heading determinationsystem comprising: a plurality of global positioning system receiversmounted to said aircraft with one of said global position receiversmounted to a front portion, one to a rear portion, one to a left wingportion, and one to a right wing portion of said aircraft, and adetermination processor coupled to said global positioning systemreceiver, said determination processor capable of calculating andassessing position, attitude, and heading of said aircraft; and saiddetermination processor system capable of determining and monitoring thearea proximate said aircraft and an area outside the area proximate saidaircraft; said fuzzy logic controller communicating with said thrustvectoring flight control system; an adjustable nozzle coupled to saidexhaust thrust port of said engine, said adjustable nozzle angularlyadjustable to direct thrust of said engine in a direction responsive tosaid fuzzy logic controller; an aerodynamic flight control systemcoupled to said fuzzy logic controller, said aerodynamic flight controlsystem comprising: a flap control system, an aileron control system, astabilizer control system, a communications system capable ofbroadcasting a signal to a ground station; a three dimensional displaydevice for providing relative air craft positions, aircraftidentification information and immediate sense of depth perception; aterrain map containing geographic information related to terrain of anarea proximate to said aircraft.
 31. A method of using a fuzzy logicbased flight control system, capable of outputting a signal, for a jetengine equipped aircraft having a thrust vectoring flight controlsystem, said method including the acts of: operating a thrust vectoringflight control system to affect the flight of said aircraft; outputtinga signal from said fuzzy logic controller to said thrust vectoringflight control system; actuating said thrust vectoring flight controlsystem responsive to said output signal.
 32. The method of using a fuzzylogic based flight control system according to claim 31 wherein saidaircraft includes an aerodynamic flight control system, furthercomprising the act of outputting a signal from said fuzzy logiccontroller to said aerodynamic flight control system.
 33. The method ofusing a fuzzy logic based flight control system according to claim 32wherein the act of using an aerodynamic flight control system furthercomprises the act of controlling control surfaces of the aircraft.
 34. Afuzzy logic method for controlling an aircraft comprising the acts of:obtaining input variables related to the aircraft, including altitude ofthe aircraft and wind shear magnitude in proximity of the aircraft, andcommunicating the input variables to a fuzzy logic controller,fuzzifying the input variables into input fuzzy sets by using the fuzzylogic controller, obtaining fuzzied output variables from the fuzzifiedinput variables, using the fuzzified output varibles to calculate crispoutput values for controlling the aircraft, and executing commands basedon the crisp output values wherein the commands control the aircraft.35. The fuzzy logic method for controlling an aircraft according toclaim 34 wherein the act of obtaining input variables further comprisesthe act of obtaining air speed of the aircraft.
 36. The fuzzy logicmethod for controlling an aircraft in an emergency situation accordingto claim 35 wherein the act of obtaining input variables furthercomprises the act of obtaining proximity parameters of the aircraft toother aircraft and objects.
 37. A fuzzy logic method for controlling anaircraft comprising the acts of: obtaining input variables related tothe aircraft and communicating the input variables to a fuzzy logiccontroller, fuzzifying the input variables into input fuzzy sets byusing the fuzzy logic controller, obtaining fuzzied output variablesfrom the fuzzified input variables, using the fuzzified output variblesto calculate crisp output values for controlling the aircraft, executingcommands based on the crisp output values wherein the commands controlthe aircraft, and using a thrust vectoring system coupled to theaircraft wherein the thrust vectoring system is angularly adjustable inthrust and provides thrust magnitude to the aircraft.
 38. The fuzzylogic method for controlling an aircraft according to claim 37 furthercomprising the act of obtaining current thrust magnitude of the thrustvectoring system.
 39. The fuzzy logic method for controlling an aircraftaccording to claim 38 further comprising the act of obtaining currentthrust angle of the thrust vectoring system.
 40. A fuzzy logic methodfor controlling an aircraft comprising the acts of: obtaining inputvariables related to the aircraft, including altitude of the aircraftand wind shear magnitude in proximity of the aircraft, and communicatingthe input variables to a fuzzy logic controller, fuzzifying the inputvariables into input fuzzy sets by using the fuzzy logic controller,obtaining fuzzied output variables from the fuzzified input variables,at least some of the output variables being thrust vectoring flightcontrol variables, using the fuzzified output varibles to calculatecrisp output values for controlling the aircraft, and executing commandsbased on the crisp output values wherein the commands control theaircraft, at least some of the commands being thrust vectoring flightcontrol commands.
 41. The fuzzy logic method for controlling an aircraftaccording to claim 40 wherein one of the thrust vectoring flight controlvariables is a thrust vectoring nozzle angle variable and one of thethrust vectoring flight control commands is a thrust vectoring nozzleangle command for controlling thrust nozzle angle of a thrust vectoringflight control system in controlling the aircraft.
 42. A fuzzy logicmethod for controlling an aircraft comprising the acts of: obtaininginput variables related to the aircraft and communicating the inputvariables to a fuzzy logic controller, fuzzifying the input variablesinto input fuzzy sets by using the fuzzy logic controller, obtainingfuzzied output variables from the fuzzified input variables, at leastsome of the output variables being aerodynamic flight control variables,using the fuzzified output varibles to calculate crisp output values forcontrolling the aircraft, and executing commands based on the crispoutput values wherein the commands control the aircraft, at least someof the commands being aerodynamic flight control commands, wherein oneof the aerodynamic flight control variables is an engine thrustmagnitude variable and one of the aerodynamic flight control commands isan engine thrust magnitude command for controlling engine thrust of atleast one engine of the aircraft in controlling the aircraft in theemergency situation.
 43. A fuzzy logic method for controlling anaircraft comprising the acts of: obtaining input variables related tothe aircraft and communicating the input variables to a fuzzy logiccontroller, fuzzifying the input variables into input fuzzy sets byusing the fuzzy logic controller, obtaining fuzzied thrust vectoringflight control variables and aerodynamic flight control variables fromthe fuzzified input variables, using the fuzzified output varibles tocalculate crisp output values for controlling the aircraft, andexecuting commands based on the crisp output values wherein the commandscontrol the aircraft and are thrust vectoring flight control commandsand aerodynamic flight control variables.
 44. The fuzzy logic method forcontrolling an aircraft according to claim 43 further comprising the actof determining total thrust lift for the emergency situation wherein thetotal thrust lift is calculated from a sum of thrust from thrustvectoring flight control commands and thrust from aerodynamic flightcontrol commands.
 45. The fuzzy logic method for controlling an aircraftaccording to claim 44 further comprising the act of determining a ratioof thrust from thrust vectoring flight control commands to total thrust.46. The fuzzy logic method for controlling an aircraft according toclaim 44 further comprising the act of determining a ratio of thrustfrom aerodynamic flight control commands to total thrust.
 47. The fuzzylogic method for controlling an aircraft according to claim 44 whereinthe act of determining total thrust lift further comprises the act ofusing inference rules to determine the total thrust lift.